1. Field
The present disclosure relates generally to methods and apparatus to optimize power consumption and signaling data overhead in mobile communication devices, and more specifically to methods and apparatus to optimize power consumption in mobile devices having high power consumption and signaling overhead due to, among other things, data applications, such as in smart phone devices, by optimizing a signal release time.
2. Background
With the advent of smartphones and data cards, wireless data applications have taken mobile connectivity and workforce mobility to greater levels. Smartphone and data cards allow users to access wireless Internet on the go with high data rate connectivity whenever and wherever desired. The resultant growth in data traffic has been exponential.
A problem that was not foreseen in the prior art with such growth is that the communication network dimension, which used to be focused on “user traffic”, now has a “signaling overload” issue due to the this growth in data traffic due to the popularity of smartphone applications. This is problematic for a communication network (e.g., 3G or 4G networks utilizing 3GPP technologies such as Universal Mobile Telecommunications System (UMTS), High-Speed Packet Access (HSPA), Long Term Evolution (LTE), Evolved HSPA (HSPA+), etc.) as the signaling overhead may take up to 30-40% of cell power utilization based on known field investigations. This signaling overhead may comprise Packet switch (PS) Signaling as well as other signaling.
Power consumption of an advanced mobile device, such a smartphone, is also a critical issue affecting battery life. If a mobile device is put in an “always-on” state (i.e., connected state), this can reduce the signaling overhead and reduce the signaling latency caused by the time delay arising each time a call is setup and then released, but increases power consumption. On the other hand, if a mobile device is put into a low power consumption state (e.g. idle state), the battery life can be extended, but with increased time delay for call setup and signaling overhead. In a particular known situation where a mobile device remains “on” for a prolonged period in a power-hungry state in 3GPP, for example, if a data call, such as browsing a web page, lasts 11.8 seconds from launch to finish, there will be a subsequent DCH timeout period of 9 seconds. During this 9 second timeout period, a mobile device may still draw a high current load (e.g., 300 mA). Further, after the DCH timeout, a still subsequent Forward Access Channel (FACH) timeout of another 11 seconds occurs at a somewhat reduced, yet still substantial, current load. Thus, in this example the entire process from start of a data call to an idle state lasts for almost 33 seconds, with 20 of those seconds due to signaling overhead with an attendant higher current loading in the mobile device. This is an issue that needs to be addressed through optimization to try to reduce signaling overhead and signaling latency, while also trying to minimize power consumption as much as possible.
In 3GPP standards (Release 7 and onwards), there exist known features to resolve the above issues of signaling latency, signaling overhead, and power consumption. As one example, a known “Enhanced Cell_FACH” state requires the mobile device to stay in a power efficient state while the RRC (Radio Resource Control that is at the network layer) remains connected. Another known feature is termed “fast dormancy,” which allows a mobile device the flexibility to request RRC state transition from a “power-hungry” state to a power-efficient state upon detection of data session inactivity. Nonetheless, even with these features, there still exists a need to further optimize power consumption, signaling latency, and signaling overhead.